Stent and stent connection interface

ABSTRACT

A stent with a common connection interface, and a method and platform used to create a stent with a common connection interface is described. A common connection interface used to connect a stent to a pusher is described.

RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S. patentapplication Ser. No. 16/127,136 filed Sep. 10, 2018 entitled Stent AndStent Connection Interface, which claims benefit of and priority to U.S.Provisional Application Ser. No. 62/563,570 filed Sep. 26, 2017 entitledStent with a Single End Loop, both of which are hereby incorporatedherein by reference in their entireties.

BACKGROUND OF THE INVENTION

Stents are used for various therapeutic purposes within the vasculature,including opening vessels, flow diversion to limit blood flow to aproblematic region such as an aneurysm, or as a scaffold to retain othertherapeutic material within a target region.

Delivery of stents can be difficult for several reasons. Many stents endin a looped end configuration with a plurality of loops and most stentdelivery systems must connect to one or more of these loops to deliverthe stents. Stent delivery systems which hold all the loops aredifficult since the stents are delivered through relatively smallcatheters, leaving little room for a delivery design which can grip allthe loops. Delivery designs or systems which hold only one loop of theseveral loops are problematic since the stent is only being partiallycontrolled during delivery. Since stents generally have shape-memory andtherefore adopt their expanded shapes quickly once they are releasedfrom the delivery catheter, positioning and repositioning stents afterdelivery is also an issue.

SUMMARY OF THE INVENTION

The following embodiments deal with a stent connection interface whichallows multiple stent loops/flares to combine into a common connection,thereby allowing for easier control over a stent during the deliveryprocess.

In one embodiment, a stent connection interface is described. The stentconnection interface combines pairs of end stent loops into a commonconnection.

In one embodiment, a stent is described. The stent has end loops on atleast the proximal end of the stent, and the end loops converge into acommon connection region by a stent connection interface. The stentconnection interface, in turn, connects to a stent delivery mechanism(e.g., a pusher) which is used to control and deliver the stent.

In one embodiment, a stent is described where the stent has a pluralityof end loops converging into a common connection region/interface.

In one embodiment, a stent delivery system is described. The deliverysystem comprises a pusher used to mechanically grasp and position thestent. The stent utilizes a stent connection interface to create acommon connection out of a plurality of end loops, the common connectionis connected to the pusher where the pusher is used to position thestent.

In one embodiment, a method of creating a stent having a commonconnection is described. The method comprises taking a stent having aplurality of end loops and connecting a stent connection interface whichcombines pairs of end loops into a common connection area.

In one embodiment, a mandrel is described which is used to create astent having a common connection. The mandrel includes a plurality ofgrooves which accommodate a plurality of stent wires, and the pluralityof grooves are patterned such that multiple wires coalesce into a commonconnection interface.

In one embodiment, a scaffold is described which is used to create astent having a common connection. The scaffold includes a plurality ofchannels which accommodate a plurality of stent wires, and the pluralityof channels are patterned such that multiple wires coalesce into acommon connection interface.

In one embodiment, a stent delivery system is described where the stentdelivery system has a pusher which attaches to and detaches from acommon connection of a stent.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects, features and advantages of which embodiments ofthe invention are capable of will be apparent and elucidated from thefollowing description of embodiments of the present invention, in which:

FIG. 1 illustrates a stent with a plurality of end loops or end flares,according to one embodiment.

FIG. 2 illustrates an end loop or end flare of a stent, according to oneembodiment.

FIG. 3 illustrates a stent with bands use to bind wires which form aplurality of end loops or flares, according to one embodiment.

FIG. 4 illustrates a stent utilizing a fish-hook configuration to bindwire pairs, according to one embodiment.

FIG. 5 illustrates a mandrel used to wind a stent, according to oneembodiment.

FIGS. 6, 7, 8, 9, 10, and 11 illustrate a groove configuration on amandrel, according to various embodiments.

FIG. 12 illustrate a mandrel used to wind a stent, according to oneembodiment.

FIG. 13 illustrates a mandrel used to wind a stent, according to oneembodiment.

FIG. 14 a illustrates a ring configuration of a stent, according to oneembodiment.

FIG. 14 b illustrates a ring configuration of a stent, according to oneembodiment.

FIG. 14 c illustrates a common connection interface of a stent,according to one embodiment.

FIGS. 14 d-14 e illustrate a connection point between a stent loop and awire element, according to various embodiments.

FIG. 15 a illustrates a stent delivery system, according to oneembodiment.

FIG. 15 b illustrates a stent delivery system, according to oneembodiment.

FIGS. 16-18 illustrate a stent delivery system including a pusher, stentconnection interface, and stent wires, according to various embodiment.

FIGS. 19-20 illustrate a stent delivery system, according to oneembodiment.

FIG. 21 illustrates a stent delivery system, according to oneembodiment.

DESCRIPTION OF EMBODIMENTS

Stents are used for a variety of reasons in the vasculature. Forexample, propping open vessels to restore blood flow, flow diversion tolimit blood flow to a problematic region such as an aneurysm, or as ascaffold to retain other therapeutic material within a target region.Many stents use a plurality of end loops or end flares (e.g., radiallyflared loops) at either end of the stent; wherein the end loops orflares help anchor the vessel to a particular spot in the vasculature tominimize the chance that the stent will move after deployment. U.S. Pat.Nos. 9,867,725 and 9,439,791 disclose various stent embodiments havingend loops or flares, and both patents are hereby incorporated byreference in their entirety.

FIG. 1 shows one example of a stent having a number of end loops ateither end of the stent that can radially flare outwards from the mainbody of the stent in its expanded configuration. These end loops/flarescan be created in a number of ways. For example, the stent can have aone-layer or two-layer configuration. In one example, further describedin U.S. Pat. No. 9,867,725 9,439,791 which were earlier incorporated byreference, the stent has an inner and outer layer, where the outer layeris comprised of a wire braid wound over a mandrel to impart a number offlares or loops which protrude from the stent at both ends. A stent canalso utilize a single layer comprised of one or more wires wound into aparticular pattern, where each end of the stent includes a number offlares or loops. Such a stent is described in the patents referenced andincorporated by reference above.

Other stents can utilize a dual or two-layer configuration where theouter layer is formed of a series of wire pairs where each wire pairforms a flare or loop at the ends of the stent. One such stent utilizingthis configuration is described in US Published Application No.2017/0079812, which is hereby incorporated by reference in its entirety.

Stent 100 shown in FIG. 1 has a plurality of loops or flares at each endof the stent that extend both longitudinally and radially outward fromthe main body of the stent. Some of the loops are shorter 107 and someare longer 104, as shown best in FIG. 2 . These short and long loops areplaced next to each other in an alternating pattern so that one longloop is next to one short loop, which in turn is next to a long loop,etc. Various loop combinations are possible, for instance, each end ofthe stent can have 6 loops (comprised of 3 long loops and 3 short loops,in the pattern defined earlier where the loops alternate), or 8 loops(comprised of 4 short loops and 4 long loops, in the pattern definedearlier where the loops alternate), or more or fewer loops.

In one embodiment, shown in FIG. 2 , the long flares or loops 104 mayutilize a tantalum wire 105 for radiopacity, where the tantalum wire iswound between the inner and the outer layer of a dual layer stent to aidin binding the layers together. This wire 05 terminates with a coil 106on one or more of the long loops 104. These loops or flares servevarious purposes, including helping to anchor the stent in thevasculature to prevent movement after the stent is deployed as well ashelping to prop the stent open as it is deployed from the deliverycatheter. Though long and short loops are not necessary (e.g., in otherembodiments the stent can have a series of equally sized end loops), thepresence of long and short loops offers some advantages in terms ofdistributing friction circumferentially though/around a radial region ofa delivery catheter when the stent is being deployed through thedelivery catheter.

Delivering a stent with these end loops can be difficult since each looprepresents a different and separate grasping interface. Designing adelivery system that can grasp all of the loops can be challenging sinceeach loop represents a different contact interface spreadcircumferentially and peripherally around the stent. Meanwhile,utilizing a delivery system that mechanically grasps only one of theseveral loops can limit control of the stent during the delivery processsince only a small portion of the stent is being physically controlled.The following embodiments seek to address this problem by utilizing aconnection interface which connects to these end loops or flares tocreate a common connection region which is then connected to a deliverysystem to deliver the stent.

Stent 100 is preferably comprised of metallic wire, meaning the stentitself as well as the end loops on either end of the stent are comprisedof metallic wire such as nitinol—although other variations could involvethe stent being comprised of different materials such as polymers.Alternative stent construction configurations could also utilize DFT ordrawn-filled tubing, which is typically comprised of a radiopaque core(e.g. platinum, tantalum, gold, silver, titanium or tungstenwire/element) surrounded by a thin metallic (e.g. nitinol) jacket—DFToffers the advantage of radiopacity, so a stent comprised of DFT wherethe DFT comprises some or all of the metallic mesh will have heightenedradiopaque imaging properties and will not necessarily need additionalradiopaque wires/coils to aid in visualization. In one embodiment, thestent is a dual layer stent having an inner layer and an outer layer,where the flares at both ends of the stent are located on the outerlayer. The outer layer, which includes long flares 104 and short flares107, is preferably made of a multiple wire braid where pairs of wiresconverge to create the triangular flares best shown in FIG. 2 . In otherwords, two separate wires converge and then connect at or near the endor tip of the flare/loop to form the flare/loop. For instance, a stentcomprising an outer layer having four short flares 107 and four longflares 104 is preferably made of a sixteen-wire braid total forming theeight flares (comprised of four long flares 104 and four short flares107). The wire pairs are normally welded together or alternativelyaffixed together by a mechanical cap 108 that is welded to the two wireends of the short flares/loops 107 and long flares/loops 104 at eitherend of the stent—as shown in FIG. 3 , and discussed in more detail inU.S. Pub. No. 2017/0079812, the contents of which are incorporated byreference.

Alternatively, each wire can be fish-hooked or bent back at the ends,and then passed through the other wire as shown in FIG. 4 to create themechanical connection. A first wire is fish-hooked or bent back andwelded to create a circular loop, the second wire is then trackedthrough this loop and bent back and welded at a proximal location alongthe second wire to create the connection between the two wires. Thesestent end concepts—including the capped end configuration and thefish-hooked end configuration—are discussed in more detail in USPublished Application No. 2017/0079812, which was earlier incorporatedby reference in its entirety.

To create the stent winding pattern and shape, a mandrel is used wherethe wires comprising the stent are wound over the mandrel to create thestent shape. The stent is often then heat set over the mandrel to imparta shape memory into the stent, such that the stent will adopt itsexpanded, shape memory configuration when deployed from a deliverycatheter. The following embodiments utilize a mandrel with a number ofgrooves to accommodate the stent wires. The grooves are arranged in aparticular pattern such that the groove pattern converges into a commonconnection region such that the stent flares converge into a commonconnection region which can then be held by an implant pusher/deliverysystem. In this way, a stent is created whereby a plurality of flaresmerge to a common connection region to make stent delivery easier.

Since the flares 104, 107 are generally enlarged and protrude relativeto the stent 100 (as shown in FIG. 1 ), the mandrel used to wind thestent may also use enlarged regions used to create these flaredsections. FIG. 5 shows such a cylindrical mandrel 110 used to wind astent 100. Mandrel 110 comprises a smaller diameter middle section 112,tapered sections 114 a and 116 a which are used to create the flares andabut smaller middle section 112, and enlarged regions 114 and 116abutting the tapered sections. A first tapered section 114 a abutsenlarged end region 114 and a second tapered section 116 a abutsenlarged end region 116. Middle section 112 has the smallest diameter,enlarged regions 114 and 116 have the largest diameter, and taperedregions 114 a and 116 a have a tapered diameter such that the taperedregion tapers (e.g., linearly) between the smaller and larger diameter.

The tapered sections 114 a and 116 a contain a number of pins 118protruding radially and perpendicularly outwardly from the surface. Thewires forming the stent/stent layer are wound around the pins to createthe loop shapes. Where the stent has a series of short loops 107 andlong loops 104, the pin locations are radially spread out such that somepins 118 a are radially further out, and some pins 118 b are radiallycloser. Pins 118 a that are radially further out are used to wind thelong loops 104 and pins 118 b that are radially closer are used to windthe short loops 107. In other embodiments where the flares or loops areall of a similar size, pins along a similar radial location (e.g., onlypins 118 b or only pins 118 a) are used to wind the various stentloops—alternatively, in such embodiments, the mandrel is configured onlywith one set of pins (e.g., either pins 118 b or pins 118 a) so that thestent is solely wound around a set of similarly-placed radial pins tocreate a stent with equally sized end loops or end flares.

The pins are used to impart the flared or loop shapes in the followingmanner. In one embodiment, the one or more wires comprising the relevantstent/stent layer would be wound around the pins to impart theparticular flared loop shape, such that the wire is bent around the pinand wound back into the stent to impart the flared or looped shape. Oneexample where this embodiment can be used is where the relevant stent orstent layer incorporating the flares is made of one wire, such that theone wire is continuously woven back and forth and around the pins.Another example is where the relevant stent or stent layer is comprisedof multiple wires but each wire is used to wind a loop or flare at eachend of the stent, where one wire is used to create one loop at one endof the stent and wound back to create another loop at the other end ofthe stent, a second wire is used to create a second loop at one end ofthe stent and a second loop at the other end of the stent—in thismanner, an stent with 8 loops at either end (8 loops at one end, and 8loops at the other end) would comprise 8 wires, or one for each loop. Insome embodiments, the flared loops are formed of wire pairs, and theloops can be made in different ways. For instance, the wire pairs arewelded or capped at their ends beyond the pin location. Alternatively,one of the wires would be pulled backwards proximal of the pin and thenwelded or affixed to the other wire comprising the wire pair. With theseembodiments, the loops are formed from two distinct wires comingtogether and then affixed to each other to create the loop or flaredshape.

In order to create a common connection point or common connection regionfrom the plurality of end flares or loops at one end of the stent, oneof the mandrel sections would contain a series of channels or grooves toaccommodate the stent wires, where the wires would be placed into aparticular pattern etched or cut into the mandrel to funnel theplurality of wires into a pattern that ends in a common connectionpoint. These channels or grooves could be created in a number ofways—for instance, laser-cutting, etching, and mechanical cutting. Note,only one of the mandrel sections would need the groove pattern and notboth since the groove pattern is used only on one end of the stent sinceonly one end of the stent (e.g., the proximal end that is meant to beconnected to the delivery pusher/delivery system) needs the commonconnection interface.

This mandrel concept is shown in FIG. 6 , where enlarged mandrel section114 (which sits past tapered section 114 a used to wind the stentflares/loops) has a number of grooves etched, laser cut, or otherwisecut or imparted onto the surface. This groove pattern is shown in moredetail in FIG. 7 . Each groove/groove element 120 a-120 h can be thoughtof as an indented receiving surface which receives or accommodates thewire. The shorter, or less lengthy groove lines (e.g. groove elements120 a, 120 b, 120 d-120 g), represent wires which terminate prior to the(left) ending or common connection point/region 121 (see FIG. 7 ), theidea being several wires will gradually converge into each other beforethen converting to a common connection end region 121. Note, the nextportion of the description will expound on this groove/wire concept,however since the wires are placed into the noted groove elements, thefigure elements can interchangeably be used to describe either thegroove element or the wire which would sit within the groove element; assuch, the description can vary between using the figure elements todescribe either the groove element or the wire which sits in the grooveelement.

FIG. 8 shows a flattened view of the groove interface over the enlargedregion 114 (and/or 116) of the mandrel, and can be thought of as acomplete-view representation of the cylindrical mandrel pattern aroundthe enlarged region. In other words the pattern in FIG. 8 would beetched or cut around the circular enlarged region of the mandrel andFIG. 8 shows what this pattern would look over the entire cylindricalstructure if a single cut was made in an axial direction across enlargedcylindrical mandrel region 114 and the mandrel was then unfurled alongthis region to create a rectangular representation of the mandrel. FIG.8 shows 16 grooves, so this pattern would allow 16 wires to coalescedown to 4 wires, where the 4 wires are nested close to each other tocreate a common connection interface.

FIG. 9 shows the groove interface in more detail, where the respectivegrooves are labelled, and common connection region 121 is identified.Since the groove pattern would in fact be cylindrical since the patternis placed over the cylindrical mandrel, groove 120 a and 120 q arecomplementary in the sense that a wire placed in groove 120 a would syncup or align with a wire placed in groove 120 q such that the wires wouldbe welded to each other and thereby connect since they would align witheach other when placed over the circular mandrel. Again, FIGS. 8-9represent the entire circular mandrel so grooves 120 a-120 h are shownalready in FIGS. 6-7 and the “new” grooves 120 i-120 q represent thegrooves that sit along the rest of the cylindrical face of the mandrel.

FIG. 10 shows how the various short flares (107 a-107 d) and long flares(104 a-104 d, which it should be noted sit “closer” to the whole grooveinterface thus indicating the protruding nature of these lengthierflares) interact within the larger groove pattern. Each flare is formedof two wires, each wire within the pair is then placed within the grooveon the mandrel, where some grooves (120 c, 120 h, 120 k, 120 p) arelonger and meet in a common location to create a common connectioninterface 121—and the other grooves are shorter and terminate prior tocommon connection region 121.

In the groove pattern shown in FIGS. 8-10 , there are 16 groovesrepresenting 16 wires which would normally form 8 flares (4 short flares107 a-107 d and 4 long flares 104 a-104 d). Eight of these grooves (120b, 120 e, 120 f, 120 i, 120 j, 120 m, 120 n, and 120 a/120 q whichtogether form one element which terminates at the same location as theother grooves in the series—as discussed above in how these grooves areactually over a cylindrical mandrel and therefore the groovesaccommodate a common wire which is attached to the wire or groove 120 p)terminate at a common location and are considered the “shortest” groovesin terms of length. Four of these grooves (120 d, 120 g, 120 l, 120 o)terminate at a common location are considered “intermediate” grooveswhich are longer than the shortest grooves but do not span all the wayto the common connection interface 121. Four of these grooves (120 c,120 h, 120 k, 120 p) are the “longest” grooves which combine to createthe common connection interface 121 which connects to the deliverypusher. The 16 initial wires forming the 8 “flares” or “loops” thusmerge down to 4 wires forming a common connection interface 121.

In an alternate embodiment, the 4 wires 120 c, 120 h, 120 k, 120 pforming common connection region 121 can further be condensed. Forinstance, wire 120 c and wire 120 h can be attached to each other, andwires 120 k and 120 p can also be attached to each other, creating acommon connection region comprising two wires. These two wires can thenoptionally be attached to each other at another location to produce acommon connection region comprising one more. Therefore, although FIG.10 shows a common connection region 121 comprising four wires, it ispossible to create a common connection region comprising even fewerwires. This concept will be explained in more detail later in thespecification, when the mechanical connection between the commonconnection region 121 and the delivery pusher is discussed in furtherdetail.

After the wires are placed into these grooves, the portion of the wiressitting beyond the grooves are trimmed since different wires will havedifferent lengths corresponding to the respective groove lengths. Forexample, the stent wire sitting in groove 120 b would be shorter thanthe stent wire sitting within groove 120 c since groove 120 c is longer,therefore the portion of the stent wire sitting beyond the end of thegroove 120 b will be trimmed. After this trimming step is taken, thestent itself can be heat set to impart a shape memory and then the wiresare removed from the mandrel. The wires still have to be removed fromthe grooves and attached to each other at their respective groovelocations, therefore, for example, wire 120 b is attached along longerwire 120 c. This attachment can be done in a number of ways—forinstance, via welding, adhesive, crimp, or solder. Alternatively, amechanical connection interface such as an overlying cylindrical tubewhich has an internal diameter large enough to contain the various wirescan be used to bind two or more wires. In an alternative arrangement,the heat setting step to impart the shape memory can be taken after thevarious wires are attached to each other to create the “step-down”pattern culminating in common connection region 121.

With the mandrel configuration shown in FIG. 5 and described earlier,the grooves sit on the larger cylindrical mandrel region 114 where thewires that form the stent flares are drawn over the enlarged mandrelface into grooves on mandrel region 114. In order to create a commonconnection interface, all or part of the mandrel can, in one example,have a smaller diameter section on the terminal end of the larger region114 so that the end wires taper down to a smaller diameter and can beheat-set into this smaller diameter shape. Alternatively, a mandrelconfiguration like that shown in FIG. 12 can be used where the pins 118used to wind the end loops or flares of the stent are on an enlargedregion 122 a and 122 b of the mandrel. Radially smaller sections 124 aand 124 b are adjacent these enlarged regions and the groove patterninterface sits on either one of these regions (in practicality, asdescribed earlier, only one end of the mandrel needs the grooves sincethe common connection region 121 is only needed on one end of the stentwhich connects to the delivery pusher). The advantage of thisconfiguration (where the groove pattern 120 a-120 q shown in FIG. 10 isimparted on the smaller mandrel section 124 a/124 b) is that the wiresections connected to the end loops will naturally assume a radiallysmaller configuration, making it so that the common connection interfaceformed of the four “grooves” 120 c, 120 h, 120 k, 120 p will be locatedclosely together, especially after the stent is heat set over themandrel.

FIG. 13 shows an alternative mandrel configuration where a pin-lessinterface is used to create the stent flares/loops. A smaller radialregion 128 sits in the middle of the mandrel and is used to wind themajority of the stent. A larger region 130 a, 130 b at both ends helpscreate the loop or flare, and both regions 130 a and 130 b contain anumber of channels 126 that the pairs of wires forming the loops orflares are placed into—in other words, each channel 126 accommodates twowires. Since the flares are created by the wire pairs being placed intothe channels, a pin is not needed to create the loops or flares, ratherthe loops/flares are created by the wire pairs being pulled into thechannels which sit on the enlarged radial region 130 a/130 b. A numberof screws 132 are optionally placed radially around the enlarged regions130 a, 130 b where the circular region housing the screws overlap partof the channels 126 b such that when the screws are tightened, theyoverlie the wires in the channels thus ensuring the wires do not fallout of the channels. Though not shown, the groove configuration shown inFIG. 10 would be located along the enlarged region of the mandrel 130 anear where the wire pairs first combine into a channel 126. Therefore,the channels would branch off into the groove configuration of FIG. 10somewhere near the initial region where the wire pairs combine into eachchannel. In another embodiment, a first enlarged region would house theinitial channel 126 where the enlarged region is used to create theenlarged flares or loops; and a smaller radially recessed region(similar to regions 124 a/124 b or FIG. 12 ) then utilizes the grooveconfiguration of FIG. 10 to create the common connection interface fromthe plurality of wires/wire pairs which form one end of the stent.

Though the mandrels have primarily been described as having grooves orchannels to accommodate the wires, alternative configurations canutilize a series of wire holding elements placed over the mandrel wherethe holders/holding elements form the grooves/channels to accommodatethe wires. In this way, a guiding interface is formed to guide thewires, however no cuts or recesses on the mandrel would be necessary,rather the guide channels would simply be built over the particularsection of the mandrel. In one embodiment, the guiding interface is ascaffold that is placed over the mandrel and the mandrel can containsrecesses, where a removable pin or retention element is used totemporarily secure the scaffold to the recesses of the mandrel. In thisway, the overlying guide interface can be temporarily affixed over themandrel to guide the stent wires into a pattern like the pattern shownin FIGS. 8-10 , to culminate into a common connection region 121.

Alternatively, a scaffolding interface can connect to the loops of thestent where the scaffolding interface has the guide holders describedabove to guide the particular wires in a particular way, where the wiressit within the guide holders. With this embodiment, there would be noneed for a scaffold or guiding interface to be “built over” the mandrel,rather the mandrel section would terminate with the part of the mandrelaccommodating the loops. The scaffold interface would then be placedadjacent to the end loops, where the scaffold interface is comprised ofa series of holders forming a pattern corresponding to the grooveinterface embodiments shown in FIGS. 8-10 . The scaffolding interfacecan still adopt a generally circular profile to emulate the circularmandrel surface, however the scaffold interface would basically containa series of wire holding elements which together adopt a circularprofile (to correspond to the cylindrical shape of the stent and thecircular-type shape of the stent ends and how the stent loops proceedcircularly around the end of the stent) where the holding elementscontain the wires of the stent. In this manner, a wire guide mechanismcan be implemented independent of the stent mandrel.

Alternatively still, the scaffolding interface can adopt a mandrelconfiguration but not actually be part of the physical mandrel itselfwhich is used to wind the stent. The scaffolding interface would be acircular element with a wire-holding pattern cut into the surface (asgrooves) or built over the interface (as protruding holding elements).In this embodiment, the scaffolding interface is best thought of as adetached, movable mandrel which can be placed adjacent to the end stentloops/flares, such that the stent wires can then be drawn through thewire guides of the movable mandrel.

In another embodiment, the entire groove pattern illustratively shown inFIGS. 8-10 is a prefabricated entity which is either comprised of wiresor a laser cut sheet, such that the wires or retained elements of thelaser cut sheet are patterned similar to the groove pattern of FIGS.8-10 . The entire prefabricated entity is the attached to the end loopsof the stent through adhesives, mechanical means such as ties, orwelding. In this way, the stent with its end loops is a first separatestructure, the second attachable prefabricated entity which reduces thestent flare pattern to a common connection interface 121 is a secondseparate structure, and the two structures are attached together tocreate a stent which includes a common connection region 121.

Some of the embodiments presented herein utilize a separate wirestructure or laser-cut structure which connects to the stent flareregion to create a common connection interface. For example, a scaffoldor frame structure which connects to the stent flares to guide the stentwires in a particular direction. FIG. 11 shows such an embodiment, wherea scaffold or frame element connects to the stent flares (both shortflares 107 a-107 d and long flares 104 a-104 d). The frame elementcomprises a series of channel elements 140 a-140 d, where separate wireelements sit within the channel elements such that the wires condensedown to a smaller common connection interface 121. The frame element canbe thought of as a fixture connected to the stent/stent flares, and aseries of pins 144 can be used over the flares to bind the flares to theconnecting frame fixture. In FIG. 12 , each long flare 104 a-104 d isconnected to a corresponding frame channel element 140 a-140 d. Theframe channel element 140 a-104 d accommodates a wire 142 a-142 d. Theend part of the frame channel condenses down to a smaller element 141 a,141 b (whereby elements 140 a and 140 b meld into element 141 a andelements 140 c and 140 d meld into element 141 b, where frame elements141 a and 141 b hold a separate wire 1413 a and 143 b. Wire 142 a and142 b are connected at their converging section (e.g. through welding),and then are connected to wire 143 a to form one connected wire.Similarly, wires 142 c and 142 d are connected at their convergingsection and then connected to wire 143 b to form one connected wire.Wires 140 a-140 d are further connected to the corresponding flareelement 104 a-104 d. In this way, each long flare 104 a-104 d isconnected, such that four long flares 104 a-104 d converge down into atwo-wire common connection interface 121. In one embodiment, wires 143 aand 143 b can then be connected to form a one wire common connectioninterface 121. While in the embodiment of FIG. 10 the wires of the stentloops are then wound into a particular pattern, here the stent loops(e.g. longer stent flares 104 a-104 d) are used as a connectionmechanism to a frame, where the frame provides a holding interface forwires which in turn connect to the longer stent flares 104 a-104 d).

The following embodiments utilize an alternative configuration to linkthe stent flares together, these embodiments utilize using wires to linkthe stent flares together in a ring like pattern and then connecting acommon connection interface to this ring-like pattern. Since the flaresform a generally circular pattern around the end of the stent, as shownin FIGS. 1-4 , the flares can in turn be connected together with wiresto connect the flares in a circular pattern where one or more wiresconnect between the flares to form a circular connection pattern. Acommon connection interface 121 connects to the ring-type shape, wherethe common connection interface can be a wire or tube. In one example,the common connection interface is a wire that connects to solely one ofthe stent flares—in this way, all the stent flares are connectedtogether in a ring-like pattern, while a single common connectioninterface is then connected to only one of the stent flares. Thisconfiguration is generally shown in FIG. 14 a where the stent loops 104a, 104 b, 107 a (just three loops are illustratively shown for ease)connect to a circular ring like pattern 150. Note, in the embodimentshown separate wire elements 154 connect between the ring and the stentflares, however as described above, the stent loops can directly connectto each other to form the ring pattern 150 as well.

In another embodiment, half of the stent flares are connected with afirst wire or series of wires and half of the remaining stent flares areconnected with a second wire or series of wires. This can be thought ofas a first linked “half-ring” and a second linked “half-ring”. Eachhalf-ring will have its own connected common connection interface,therefore a two-wire common connection interface is created, where afirst wire is connected to the first half-ring, and a second wire isconnected to the second half-ring.

In another embodiment, a braid of wires is used to connect the variousflares together and this braid of wires forms a generally circularpattern connecting the various stent loops/flares together, where thiswire braid forms the ring-type shape. In another embodiment, the shortflares are all connected by one or more wires and the long flares areseparately connected by one or more wires such that both the shortflares and long flares are separately combined by two separate rings.Another binding structure, such as a wire, then connects the two rings.

In another embodiment, a circular pattern is utilized to connect thevarious flares, however the circular pattern is tapered. Thisconfiguration is shown in FIG. 14 b where a tapered ring pattern 152 isconnected to the stent flares 104 a, 107 a, 104 b. Note, in the figureseparate wire elements 154 connect between the ring 152 and the stentflares, however as described above, the stent loops can directly connectto each other to form the tapered ring pattern 152 as well. Oneadvantage to this tapered ring design is that the common connectioninterface can project from the part of the ring that projects the most(e.g., the bottom left part of the ring in FIG. 14 b ) to create aconnection point that diverges from the rest of the stent. This type ofconfiguration is also shown in FIG. 15 a. The tapered ring configurationcan also be produced utilizing only two stent flares, where a recessedportion of the ring (e.g. the top ring portion of FIGS. 14 b /15 a) isconnected to the first flare, and a projecting portion of the ring(e.g., the bottom ring portion of FIGS. 14 b /15 a) is connected to thesecond flare, and a lengthier wire spans from the second flare to theprojecting portion of the ring as highlighted in FIG. 14 b.

Alternatively, the common connection interface 121 can comprise a numberof wires 154 which directly connect to the stent flares and converge toa common connection point—as shown in FIG. 14 c.

FIGS. 14 a-14 c and the description above generally touch on a conceptwhere wire elements 154 are connected directly to the stent flares,either to form a common ring or to form a direct connection point. FIG.14 d illustrates how the wires 154 can be connected to the stent flareregion (illustratively shown as long flare 104 a comprised of a firstwire 158 a and second wire 158 b). Here, the wire element 154 is placedin between a pair of wires comprising the stent flare, and a number ofspot welds 156 are placed between the wire 154 and stent flare 104 a tocreate the connection. The weld points 156 can be spaced out indifferent locations relative to the two wires forming the flare region104 a. Also, though the figure shows the wires forming flare region 104a connected at the same point along wire 154, this can be spread suchthat the first wire 158 a sits at another point along wire element 154compared to second wire 158 b (e.g. 158 a sitting further along element154 as compared to 158 b). Spreading out the wire and weld locationsoffers advantages in terms of spreading out high stiffness regions sincethe welded connection points will represent areas of high stiffness, inturn making deployment from the catheter and retraction back into thecatheter easier.

Please note, different stent flare embodiments are discussed earlierwhere some embodiments utilize a pair of wires converging to form astent flare, and other embodiments utilize a single wire which creates alooped or flared end shape. In the latter concept, the wire comprisingthe flared loop 104 a is cut to create a gap and the separate wire 154would then be connected in this region. In another embodiment, thisconnection element is directly connected to the stent loop 104 a suchthat two additional wires forming the “V” shape connect to the stentloop and wire element 154 is connected within this V-shape to compressthe stent flare region down to a one wire element 154. The differencehere is that the wire element 154 is connected to another crown elementbuilt over the stent flare 104 a rather than the wire element 154 beingdirectly connected to the stent flare. This configuration is best shownin FIG. 14 e where loop 104 a has element 160 built over it when thenconnects down to a single wire element 154.

The preceding description focused on the mandrel and/or frame, grooveinterface, and techniques used to create a stent having a commonconnection region at one end of the stent, where several wires condensedown into a smaller group of wires forming a common connection region121. The following description will discuss how the common connectionregion interacts with the delivery pusher to connect the stent to thedelivery pusher.

Stents are generally connected to a mechanical pusher, which takes theform of a rod or tube used to push the stent through a delivery catheterand to the target region. With the stents described herein which utilizea common connection interface, the stent 100 will taper down to a commonconnection interface 121, and this common connection interface 121 thenconnects to a pusher 134—as shown in FIG. 15 a . FIG. 15 b offers asimilar view as FIG. 15 a , except shows the stent flares in more detailand therefore represents a view of the stent, stent connectioninterface, and pusher when the stent is in its expanded state such thatthe flares radially project larger than the rest of the stent. Thedetails of the connection between pusher 134 and stent common connectioninterface 121 is shown in more detail in FIGS. 16-18 and will bedescribed.

As shown in FIG. 16 , the common connection interface/region 121 iscomprised of the four wires 120 c, 120 h, 120 k, 120 p (which, as shownin FIG. 10 , are condensed from the initial 8 loop/16 wireconfiguration). These four wires comprising the common connectioninterface 121, in turn, connect directly to the pusher 134. The pusheris a relatively long object and has a length corresponding to at leastroughly the length of the delivery catheter since the pusher must beable to push the stent through the entire length of the deliverycatheter and out of the delivery catheter to the target treatment site.FIGS. 16-18 can be thought of as showing the distal interface of thepusher 134 where the pusher is connected to the stent/stent connectioninterface. Some retention means 136—such as, for example, adhesive,solder, and/or a mechanical holder interface (e.g. ties, or an overlyingcylinder enclosing the distal section of pusher 134 as well as commonconnection interface 121) is used to connect the pusher to the variouswires. Detachment means commonly known to those skilled in the art—suchas a thermolytic system utilizing heat to sever or degrade the holderinterface 136, an electrolytic system, or a mechanical system (e.g.,rotational threads) are used to detach the pusher from the stent oncethe stent is deployed in the vasculature thereby freeing the stent fromthe pusher.

The earlier description discussed the common connection interface 121 ascomprised of four wires, but also mentioned how alternative wirearrangements could condense the common connection interface 121 downinto two or even one wire. FIGS. 17-18 build on this concept to utilizea one-wire and two-wire pusher connection whereby the four wires furthercondense to a condensed wire structure.

An alternative embodiment is presented in FIG. 17 where the four wiresnormally forming the common connection interface intersect into one ofthe wires 120 k, such that the one wire 120 k is the only one connectedto the pusher. In this example the other three wires are trimmed andaffixed to wire 120 k through adhesives, welding, ties, or other meansso that only one wire is directly connected to pusher 134. Retentionmeans 136, as discussed above, are used to connect the wire to thepusher 134, while a detachment system as described above is used todetach the stent from the pusher.

Another alternative embodiment is presented in FIG. 18 , where the fourwires normally forming the common connection interface 121 intersectinto two wires which connect to pusher 134. Wire 120 c attaches tolonger wire 120 h which connects to the pusher 134, and wire 120attaches to longer wire 120 k which is also connected to the pusher 134.

The attachments between wires can be created in a number of differentways as discussed earlier, including adhesives, ties, and welding (e.g.,spot welding). Multiple spot welds in different locations along thelength of the connected wires can be used to enhance the connectionstrength, or one weld point can be used to allow more flexibilitybetween the two wires. Since the attachment locations will be somewhatstiff due to the presence of the attachment medium, the attachmentpoints can be spread out or staggered along a particular wire (e.g.along a longer wire 120 c which is one of the wires comprising commonconnection interface 121) to spread out the location of these locallystiffer areas.

FIG. 19 shows another pusher system embodiment to keep a stent retainedto a pusher system during delivery. The stent is originally containedwithin a delivery catheter 162. FIG. 19 shows the configuration afterthe stent 100 is pushed out from the catheter 162. Stent 100 isconnected to a pusher 164 which is used to push the stent through thedelivery catheter 162 and out of said delivery catheter 162. The distalpart of the pusher includes two bands 166 a and 166 b, the bands can beradiopaque to aid in visualization and therefore can be consideredmarker bands; these marker bands sit along a core wire 170 that extendsdistally beyond the pusher 164—as best shown in FIG. 20 . The commonconnection mechanism 121 connects to the stent, providing a connectioninterface with the pusher. A proximal portion of the common connectionmechanism contains coils, these coils can be radiopaque to aid invisualization. Where the common connection mechanism comprises one ormore wires, these coils are simply coiled over the wire/s and projectfrom the wires such that the portion of the wires containing the coilsare thicker than other portions of the wire comprising the commonconnection interface. Since the coil section is thicker, when placedbetween the two marker bands it fixes the stent in place (eithercompletely, or only allowing a little give corresponding to whateverspace is between the marker bands 166 a, 166 b and the marker coil 168)while the marker coil 168 is contained between the two marker bands 166a and 166 b. As shown in the images, the length of the coil should besmaller than the gap between the two marker bands so that the coil iscontained within the gap. In this way, the stent is connected to thepusher. The marker coil can take on the configuration shown with markercoil 106 of FIG. 2 —with the caveat being that here the marker coilwould be placed on the common connection interface. In one example, acoil is connected to only one of the one or more common connectionmechanism wires which form common connection interface 121. In anotherexample, a coil is connected to two common connection mechanism wireswhere one wire sits on either side of the marker band thereby providinga two-tiered connection interface—as best shown in FIG. 20 . When thepusher 164 is pushed out of the delivery catheter 162, there is nolonger a restraining force and the stent and common connection interfacewill expand thereby disengaging the binding marker coil 168 from thespace between marker bands 166 a, 166 b.

Alternative embodiments similar to the deployment system of FIGS. 19-20can utilize a coil-like common connection mechanism 121 where the coiledcommon connection mechanism adopts a first elongated shape whenconstrained within the delivery catheter 162, and adopts a secondunrestrained coiled shape (its “heat-set”/“shape memory” shape) whenfreed from the delivery catheter. In this way, the common connectionmechanism 121 shortens upon delivery thereby reducing the length of thewires hanging proximally off of the stent after delivery of the stent100 as the common connection mechanism 121 adopts its non-elongatedcoiled delivery shape upon deployment from the catheter.

FIG. 21 shows an alternative embodiment where the pusher 172 ends in aring-member 174, and stent 178 has a common connection member 176 whichends in its own ring-member 176. The two ring members (pusher ringmember 174 and stent/common connection ring member 176) intersect in ajewelry chain-like manner. The pusher can utilize electrolytic orthermolytic means to sever the pusher ring member, thereby severing thepusher from the stent to deploy the stent 178. In one example, pusherring member 174 is a thread or suture and an electrode placed along thepusher proximal of this thread/suture supplies the heat to sever thethread/suture to thereby release stent 178.

The earlier description discussed the use of certain metallic materialsfor potential use within the stent, such as nitinol or drawn-filledtubing. In some embodiments, particular parts of the stent, such as thestent flares and/or the common connection interface described earliercan utilize radiopaque wires or DFT to selectively aid in imaging inthis particular region of the stent body.

Although the invention has been described in terms of particularembodiments and applications, one of ordinary skill in the art, in lightof this teaching, can generate additional embodiments and modificationswithout departing from the spirit of or exceeding the scope of theclaimed invention. Accordingly, it is to be understood that the drawingsand descriptions herein are proffered by way of example to facilitatecomprehension of the invention and should not be construed to limit thescope thereof.

What is claimed is:
 1. A stent delivery system comprising: a pusher usedto deliver a stent, the stent having a plurality of proximallypositioned end loops; and a connection interface positioned between thepusher and the stent and proximally linked to the pusher and distallylinked to the stent, the connection interface including: a distalsection having a plurality of wires, each of the plurality of wiresconnected to one of the plurality of end loops; and a proximallyadjacent section next to the distal section having less wires than thedistal section, wherein the proximally adjacent section of theconnection interface has half the number of wires than the distalsection.
 2. The stent delivery system of claim 1, wherein the connectioninterface further comprises a proximal end section connected to thepusher.
 3. The stent delivery system of claim 2, wherein the proximalend section has one or two wires.
 4. The stent delivery system of claim1, wherein the plurality of proximally positioned end loops projectradially outward.
 5. The stent delivery system of claim 1, wherein theconnection interface is independent of the stent and is mechanicallyattached to the stent.
 6. The stent delivery system of claim 1, whereinthe stent is composed of wires and each end loop is composed of twowires.
 7. A stent delivery system comprising: a pusher; a stentdelivered by the pusher, the stent having a plurality of proximallypositioned end loops, wherein the plurality of proximally positioned endloops project radially outward; and a connection interface linking thepusher to the stent, the connection interface including: a distalsection having a plurality of wires, each of the plurality of wiresconnected to one of the plurality of end loops; and a proximallyadjacent section next to the distal section having less wires than thedistal section.
 8. The stent delivery system of claim 7, wherein theconnection interface further comprises a proximal end section connectedto the pusher.
 9. The stent delivery system of claim 8, wherein theproximal end section has one or two wires.
 10. The stent delivery systemof claim 7, wherein the connection interface is independent of the stentand is mechanically attached to the stent.
 11. The stent delivery systemof claim 7, wherein the stent is composed of wires and each end loop iscomposed of two wires.
 12. The stent delivery system of claim 7, whereinthe proximally adjacent section of the connection interface has half thenumber of wires than the distal section.
 13. A stent delivery systemcomprising: a pusher; a stent delivered by the pusher, the stent havingn proximally positioned end loops where n is greater than 1; and aconnection interface linking the pusher to the stent, the connectioninterface including: a distal section having n wires, each of the nwires connected to end of the n end loops; and a proximally adjacentsection next to the distal section having less than n wires; wherein theconnection interface is independent of the stent and is mechanicallyattached to the stent.
 14. The stent delivery system of claim 13,wherein the proximally adjacent section of the connection interface hasn/2 wires.
 15. The stent delivery system of claim 13, further comprisinga proximal end section next to the proximally adjacent section, wherethe proximal end section has n/4 wires.
 16. The stent delivery system ofclaim 13, wherein the connection interface further comprises a proximalend section connected to the pusher.
 17. The stent delivery system ofclaim 16, wherein the proximal end section has one or two wires.
 18. Astent delivery system comprising: a pusher used to deliver a stent, thestent having a plurality of proximally positioned end loops; and aconnection interface positioned between the pusher and the stent andproximally linked to the pusher and distally linked to the stent, theconnection interface including: a distal section having a plurality ofwires, each of the plurality of wires connected to one of the pluralityof end loops; and a proximally adjacent section next to the distalsection having less wires than the distal section; wherein theconnection interface is independent of the stent.
 19. A stent deliverysystem comprising: a pusher used to deliver a stent, the stent having aplurality of proximally positioned end loops; and a connection interfacepositioned between the pusher and the stent and proximally linked to thepusher and distally linked to the stent, the connection interfaceincluding: a distal section having a plurality of wires, each of theplurality of wires connected to one of the plurality of end loops; and aproximally adjacent section next to the distal section having less wiresthan the distal section; wherein the connection interface ismechanically attached to the stent.